ProSoft Technology MVI56-DFCM - Manual (Page 71)

MVI56-DFCM ♦ ControlLogix Platform Reference
DF1 Half/Full Duplex Master/Slave Serial Communication Module User Manual
ProSoft Technology, Inc. Page 71 of 106
September 24, 2014
DF1 Master Protocol Specifications
The ports on the DF1 module can be individually configured as Master ports.
When configured in Master mode, the DFCM module is capable of reading and
writing data to remote DF1 devices, enabling the processor to act as a SCADA
sub-Master.
 Command List: Up to 100 commands per Master port, each fully-configurable
for function, slave address, register to/from addressing and word/byte count
 Status Data: Error codes available on an individual command basis. In
addition, a slave status list is maintained per active Master port
 Polling of Command List: User-configurable polling of commands, including
disabled, continuous, and on change of data (write only)
DF1 Slave Protocol Specifications
The module accepts DF1 commands from an attached DF1 Master unit. When in
slave mode, the module can accept DF1 commands from a Master to read/write
data stored in the mod
ule’s internal registers. This data can be derived from
other DF1 slave devices on the network through a Master port or from the
processor and is easily transferred to the processor’s data registers.
Tested Hardware Connections
Several hardware connections have been tested by ProSoft Technology or have
been customer field tested. The following physical connections have been tested
successfully:
 RA Panel view (Full Duplex point-point, DFCM as slave)
 RA Processors (Full/Half duplex, DFCM as either Master or slave)
 RA Power Monitors (485 Half-Duplex DFCM as Master)
5.2 Functional Overview
5.2.1 General Concepts
The following discussion explains several concepts that are important for
understanding module operation.
Module Power Up
On power up the module begins performing the following logical functions:
1 Initialize hardware components
o Initialize ControlLogix backplane driver
o Test and Clear all RAM
o Initialize the serial communication ports
2 Wait for Module Configuration from ControlLogix processor
3 Initialize Module Register space
4 Enable Slave Driver on selected ports
5 Enable Master Driver on selected ports